1. Field of the Invention
The present invention relates to a straddle type vehicle (e.g. two-wheeled motor vehicle), and particularly to a straddle type vehicle having an electronic throttle valve system for adjusting the amount of intake air to an internal combustion engine of the vehicle.
2. Description of Related Art
An electronic throttle valve system for electronically controlling the opening of a throttle valve to adjust the amount of intake air to an engine (internal combustion engine) can advantageously reduce emission and fuel consumption. This system has been used in some four-wheeled motor vehicles. Application of the system to two-wheeled motor vehicles has been under discussion (See JP-A-2002-106368, for example).
However, in contrast to four-wheeled motor vehicles, there are housing space limitations in the case of two-wheeled motor vehicles.
As compared to a four-wheeled motor vehicle having relatively less restrictions, the type of layout by which a mechanism is to be mounted in a two-wheeled motor vehicle cannot be determined simply, but is subject to severe restrictions.